During the operation of a storage system, data is typically stored on one or more disks of the storage system. One method by which data is stored on the disks is to initially temporarily store the data in a temporary storage location of the storage system. The temporary storage location permits high speed access to the data. Thereafter, during the operation of the storage system, the data stored in the temporary storage location is stored to the disks of the storage system. Typically, this temporary storage method is used when the disks have a slower access rate than the temporary storage location. Thus, by providing access to data quickly, the response time from data request to data delivery is short.
However, the storage system may experience downtime. For example, downtime can include situations when the storage system loses power, or perhaps, experiences a storage system failure, such as a storage system crash. Such failures result in the inability to store data to and deliver data from the storage system. Downtime can last for a few seconds or may last for longer periods of time, such as hours or days. During such downtime, data that was initially stored in the temporary storage location may not have been stored to the disks. Consequently, the data is lost. This situation may cause data inconsistencies because when the disks are accessed after the storage system recovers from the downtime, the data stored in the disks is older than the lost data stored in the temporary storage location.
In some storage systems where there is no data loss, a battery can be attached to the temporary storage location to enable the temporary storage location to continue to operate when the storage system experiences downtime. However, the downtime can last for long periods of time. During these long periods of time, the battery will discharge and the temporary storage location will once more lose data.
A solution to prevent data loss in the temporary storage location that has a discharged battery is to use a rechargeable battery to power the temporary storage location. However, although the rechargeable battery can be recharged, over time the rechargeable battery loses the ability to retain a charge. Ultimately, the storage system may operate with a temporary storage location that has a non-functioning or low performing rechargeable battery. Thus, when the storage system experiences downtime, the data stored in the temporary storage location will once more be lost.
Thus, what is needed is a method and a system to prevent losing data stored in the temporary storage location of the storage system while ensuring that the storage system does not operate with a temporary storage location that may not be able to retain data during downtime.